The largest oil sands deposit can be found in northern Alberta, Canada within the Athabasca region. Oil sands are comprised of a mixture of bitumen, solids, and water. The bitumen component of the oil sands consists of a heavy, viscous crude oil having a relatively high sulfur content. The various components can be extracted or separated and refined to generate numerous downstream commercial products. Specifically, bitumen can be separated from the oil sands to produce synthetic crude oil capable of being processed into various products.
The oil sands can be mined by truck and shovel and transported to an extraction facility. Bitumen can be removed from the oil sands by an extraction process of mixing the oil sand with hot water to form an ore-water slurry. Chemicals can optionally be added to the ore-water slurry to enhance the bitumen recovery. A well known extraction enhancement technique is to increase the pH of the slurry to increase the water-solubility of the bitumen. However, increasing the pH can also ionize organic acids and produce natural surfactants, extract the natural surfactants from the bitumen, and scavenge divalent cations, e.g., calcium and magnesium, thereby forming the metal carbonates
Traditionally, additives such as caustic soda (NaOH) and/or soda ash (Na2CO3) are added to the ore-slurry mixture to increase the pH and the water-soluble fraction of bitumen. The surfactant formation can cause emulsification during froth treatment and hinder the settling of the tailings.
During forth treatment, emulsification of released bitumen in water and suspension of fine particles in the aqueous phase can occur. Emulsification can greatly reduce the overall bitumen extraction efficiency and cause environmental problems when the process water is being disposed. Additionally, an increased tailings settling time can lead to a reduction in land reclamation and water recirculation.
Therefore, a need exits to develop a process agent that can enhance bitumen recovery and froth quality while maintaining a short settling time and high water clarity.